Hmm... I tend to oscillate between thinking I look like my nearest-in-age sister, and like my cousin.
My current avatar is a dead ringer for my sister. (One of three, and my sisters are 3/7 of my siblings, so there ya go) When I smile, I look like my paternal cousin. I think I may be the closest thing my family has to a perfect blend of our parents, actually. Not that Mom and Dad are going to be particularly happy with that realization. v_v